Can't have cold ventilation

[tranquility]

Is this the nature of the engine because whenever I want cool air ventilation (regular air not a/c), I cannot get it save for when the engine is cold. Whenever the engine goes up to operational level (which I assume is 1/2 in the temp gauge), the 'coldest' I can get is warmish air.

If useful for reference, right now, Toronto weather is a bit humid and close to 30C (or 86F).

[MDLFCS]

I don't know this is possible due to the fact that the fresh air temperature is dependent on the engine temperature.

I understand that A/C air quality is different than the fresh air, but I always have them on to control the air cabin temperature, no matter what temperature the engine is in.

I set the climate control to a higher temperature when I don't want them to be icy cold all the time with the A/C on.

[richard in NC]

Originally Posted by tranquility

Is this the nature of the engine because whenever I want cool air ventilation (regular air not a/c), I cannot get it save for when the engine is cold. Whenever the engine goes up to operational level (which I assume is 1/2 in the temp gauge), the 'coldest' I can get is warmish air.

If useful for reference, right now, Toronto weather is a bit humid and close to 30C (or 86F).

Just to make sure.... Is the center vent temp on the coldest setting?

[tranquility]

Originally Posted by richard in NC

Just to make sure.... Is the center vent temp on the coldest setting?

Yup. That's another question, why is there that setting in addition to the 2 knobs on the centre console? So that centre vent one controls the med level vents and the 2 knobs control the top and bottom vents?

[richard in NC]

Originally Posted by tranquility

Yup. That's another question, why is there that setting in addition to the 2 knobs on the centre console? So that centre vent one controls the med level vents and the 2 knobs control the top and bottom vents?

That is a multi decade BMW feature to allow the center vent temp to be adjusted independently of even an auto temp setting.

[tranquility]

Originally Posted by MDLFCS

I don't know this is possible due to the fact that the fresh air temperature is dependent on the engine temperature.

Seems like for this car the air temp is especially dependent on the engine temp, and it is usually quite warm and I can't get a cool temp unless I turn on the a/c.

[bill123]

Originally Posted by tranquility

Seems like for this car the air temp is especially dependent on the engine temp, and it is usually quite warm and I can't get a cool temp unless I turn on the a/c.

+1

[tot]

Originally Posted by tranquility

Yup. That's another question, why is there that setting in addition to the 2 knobs on the centre console? So that centre vent one controls the med level vents and the 2 knobs control the top and bottom vents?

In the center vent the hot/cold is slightly misleading. The hot setting gives you whatever the other vents are giving and cold setting gives you fresh outside air.

[RickC]

I do not have your car but I find the same thing in my 335 that I can not get outside air at the outside air temp. The engine warms it. The only way to get it cold is with the AC. It has the center knob.

On my 2004 Z4 I can get cold outside air with no modification in temp. It does not have the center knob that impact the air temp to the front vents.

[H-Doc]

Originally Posted by tot

In the center vent the hot/cold is slightly misleading. The hot setting gives you whatever the other vents are giving and cold setting gives you fresh outside air.

Well, that is how it was explained to me, as well- the dial just mixes in fresh outside air to the center vents. The purpose is to allow for cooler air to your face (for comfort, to stay awake, whatever) while you have the heat on your feet... so it's really of little use unless it's cold outside (and the "fresh" air mixed in is assumed to be cooler than the temp settings on the climate control).

In reality, however, it appears to be more than that. If it worked as above, it should act in the opposite fashion in the heat of the summer- turning to the red/right would be less fresh air and colder, A/C air, and turning toward the left/blue, would allow more fresh, albeit warm/hot air into the mix. I can verify it works correctly, however (turn to the blue gives colder air).

Even more than this, it affects all four mid level vents (including the ones over by the doors). The windshield and lower/leg vents are unaffected, of course. It seems to act more as a second temp setting/modifier for the mid-level vents.

[Marc45]

What's wrong with just using the A/C to control interior temp?

When I want a lot of fresh air, I push the button that opens the top

[tranquility]

I don't want to be using a/c 24/7. It's just too bad I can't seem to get normal cool air from the vents.

[teagueAMX]

I think the air ducts are influenced by engine compartment heat, and it may be unintentional. There was a similar compliant in the X6 forum.

Haven't been to Toronto but would guess the climate is fairly moderate up there so you're asking yourself, if I'm driving around on a nice cool day why do I need to run my air conditioner? After all, don't I use more gas with the AC on all the time? Seems like a simple enough thing to ask.

Other car manufactures allow you to use outside air just for ventilation purposes that hasn't been heated, but I believe the assumption with car manufactures now days is that the AC compressor will be engaged all the time anyway. Which is sort of like setting the thermostat in your house ventilation system. The other thing is the parasitic losses from the AC compressor being on is not as great as they used to be. Years ago they really sapped engine power and caused a significant reduction in fuel mileage. It's still true to a small extent, but it's not that significant.

For the time being adjust the temp and vents to maintain the temps that make you feel comfortable. There's really no other choice.

[tot]

Originally Posted by H-Doc

Well, that is how it was explained to me, as well- the dial just mixes in fresh outside air to the center vents. The purpose is to allow for cooler air to your face (for comfort, to stay awake, whatever) while you have the heat on your feet... so it's really of little use unless it's cold outside (and the "fresh" air mixed in is assumed to be cooler than the temp settings on the climate control).

In reality, however, it appears to be more than that. If it worked as above, it should act in the opposite fashion in the heat of the summer- turning to the red/right would be less fresh air and colder, A/C air, and turning toward the left/blue, would allow more fresh, albeit warm/hot air into the mix. I can verify it works correctly, however (turn to the blue gives colder air).

I stand corrected. I tested today the cold setting first time during hot weather and yes, the air is not warm outside air, just cold air.

[tranquility]

Originally Posted by tot

I stand corrected. I tested today the cold setting first time during hot weather and yes, the air is not warm outside air, just cold air.

Huh, you were able to get cold air (not using a/c)?

[tot]

Originally Posted by tranquility

Huh, you were able to get cold air (not using a/c)?

No, just the opposite -- the cold setting in the center vent does not give you the outside air as it is.

[MDLFCS]

The fresh air intake is under the hood of the Z4s, rather than exposing the cowl vents outside of the hood like most cars.

Although, there is a seal under hood to separate the cowl vents, it still bring the heat from the engine or lack of moving air coming through it.

[tranquility]

Reviving this thread since summer is coming up: I guess another solution is just to shut off the middle vents if one wants (cool) ventilation but not a/c. Still, w/ no vents directly aimed at the face, not sure how effective that would be.

[SammyZ4]

Forget the fan, use that AC or drop the top and enjoy the best kind of air you can...

[mcbeee]

I use the centre control knob to get cool air with the AC off, if it isn't raining I open the window or put the top down ....it is a roadster after all.

[danils]

Hi Guys,

Same issue also on my unit, I made a test placing my hand on the air intake after using the car and yes, the environment surrounding the intake is warm. It's a placement issue.

My concern is that also with A/C the evaporator is supplied with warm air so the efficiency of the A/C is reduced

[tranquility]

Originally Posted by danils

My concern is that also with A/C the evaporator is supplied with warm air so the efficiency of the A/C is reduced

No, the a/c is excellent; just that the 'regular' air is not as cool (it's still warmish due to being inadvertently heated up by the engine) as I expected even if outside air is cool.